Avoidance

Have a meal with families with infants these days, and you might get the impression that the planet is full of dietary allergens.

Dads and mums have been taught to winnow away culprits like egg whites, citrus, peanuts, berries and beef from the babies' menu. But be not beguiled. If such conventional wisdom or long-held dogma is a reliable guide - which, of course, it often is not - the food allergy rate should have been declining.

So it goes. There's no perfectly neat rule to keep allergy at bay.

Which brings us, somewhat uncomfortably, to the question of whether there is a genuine need to avoid the potential allergen like water leak from the Fukushima Daiichi nuclear plant. No one is more qualified to stir the cauldron of food allergen controversy than the United Kingdom scientists who published their landmark peanut allergy study in the New England Journal of Medicine this week.

Peanut allergy is no joke; you can get vomiting, itchy hives, a swollen tongue - or worse, die when the swelling occurs in the windpipe impeding your breathing - after one small scoop of peanut butter. Overwhelmed by the threat of peanut allergy, the scientists designed an elegant study and randomly assigned some 640 infants 4 to 11 months old with serious atopic dermatitis or egg allergy either to eating peanut regularly (three or more meals per week) or absolutely-no-peanut diet until age 5.

Contrary to those who expect infants with early introduction of peanut (as early as four months old) to be at high risk of developing peanut allergy, the scientists find that early peanut consumption leads to a far lower odds of peanut allergy at age 5.

That is a surprise to everyone. An accompanying editorial called the results "so compelling" and the rise of peanut allergies "so alarming" that guidelines for how to feed infants at risk of peanut allergies should be revised soon. None of this is to suggest that we should feed our babies whatever we want. But right now, we learn that avoidance isn't the answer.